Dietary Reference Intakes

Wouldn't it be great if your taste buds could be turned on based solely on your nutritional needs? That way, when your body needed more vitamins, your taste buds could cause an insatiable craving for a big green salad. If your taste buds had this nutritional-on switch, then meeting your body's nutrient requirements would be simple. Unfortunately, your taste buds tend to respond to flavors, and the most flavorful foods are not necessarily the most nutritious ones.

So, you must follow the Dietary Reference Intakes (DRIs), which are a set of recommendations for the proper intake of nutrients to ensure that your body is getting what it needs for good health and the prevention of disease. The DRIs include four sets of values developed by the Institute of Medicine. In this lesson, you will learn about these values and how they can help people of different genders and at different stages of life create a plan for good health.

Estimated Average Requirements (EARs)

Let's start by learning about the Estimated Average Requirements (EARs), which are the intake levels for nutrients estimated to meet the needs of half of the healthy individuals in a particular group. It might help you to recall this term and definition if you link the words average and half together; when you are average, you are halfway between good and bad.

Let's look at a made-up example to gain an understanding of EARs. Let's pretend that the estimated average requirement of cheeseburgers for a group of men over the age of 70 is three cheeseburgers per day. This means that if every man in this group consumes three daily cheeseburgers, only half of them would obtain enough cheeseburgers to meet their requirement; the other half would fall short.

So, why would we care about this value? Well, there are a couple of purposes for the EARs. First, they are used to assess the adequacy of a population's food supply, and second, they are used as the basis for calculating the RDAs for individuals.

Recommended Dietary Allowances (RDAs)

Recommended Dietary Allowances (RDAs) are the intake levels for nutrients that meet the needs of nearly all healthy individuals in a particular group. When we say nearly all, we mean about 97% of the individuals that make up a certain group. As you would imagine, the RDA will be a higher value than the EAR. So our group of men over the age of 70 might have an RDA of five cheeseburgers a day. By meeting the RDA, the men in this group would lower their risk of cheeseburger deficiency. Now, we have been joking around with the RDA of cheeseburgers, and although it would be great if we needed a daily dose of cheeseburgers for good health, this is not the case. However, RDAs are set for vitamins and minerals, and schools, hospitals and other institutions use RDA value to create nutritious meals.

Adequate Intakes (AIs)

The RDA is known for many nutrients, but not all of them. When there is not enough data to set an RDA for a nutrient, we use a different value, namely the Adequate Intakes (AIs). The AIs are the approximations of the needed nutrient intakes when no RDAs exist. For instance, we learned from our pretend example that the RDA of cheeseburgers is five per day, but we don't know the RDA of ham sandwiches, so we would assign ham sandwiches an AI. This adequate intake value is based on what healthy individuals typically eat, so AI can be used as a target amount for a certain nutrient to help plan a healthy diet.

In real life we use this adequate intake value when looking at different food components, such as fiber. Fiber is a component of plant-based foods that is not easily broken down, but supports the digestive process. According to the Dietary Guidelines for Americans 2010, fiber has an AI of 14 grams per 1,000 calories.

Tolerable Upper Intake Levels (ULs)

The final set of dietary reference intake values is the Tolerable Upper Intake Levels (ULs). This is the highest level for nutrients that nearly all healthy individuals in a particular group can reach without adverse effects. In other words, this is the most your body can tolerate, so ULs are set to help individuals avoid toxicity.

As you would imagine, this would be our highest value of all of the DRIs. For example, the UL of cheeseburgers for our group of older men might be set at nine cheeseburgers a day. You can imagine that it would be pretty hard to eat more than the UL for cheeseburgers, and this is the same for most nutrients.

In general, ULs are very high values and hard to meet just by eating foods. However, nutrient supplements may push an individual over the tolerable upper intake level for a certain nutrient. An example that can have serious consequences is the mineral iron. The UL of iron is 45 milligrams per day for most men and women; ingesting more than this amount can cause damage to vital organs in your body.

Lesson Summary

Let's review.

The Dietary Reference Intakes (DRIs) are a set of recommendations for the proper intake of nutrients. By meeting them, you ensure that your body is getting the nutrients it needs for good health and the prevention of disease. The DRIs include four sets of values.

The Estimated Average Requirements (EARs) are the intake levels for nutrients estimated to meet the needs of half of the healthy individuals in a particular group. These values help establish the adequacy of a population's food supply and are used as the basis for calculating the next DRI value we discussed, which was the Recommended Dietary Allowances (RDAs). RDAs are the intake levels for nutrients that meet the needs of nearly all healthy individuals in a particular group.

When there is not enough data to set the RDA for a nutrient, we use different values, namely the Adequate Intakes (AIs). The AIs are the approximations of the needed nutrient intakes when no RDAs exist. The final set of dietary reference intake values we discussed was the Tolerable Upper Intake Levels (ULs). This is the highest level for nutrients that nearly all healthy individuals in a particular group can reach without adverse effect.

Summary:

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